The present invention relates generally to automotive vehicle roofs and more particularly to a convertible top stack mechanism used in an automotive vehicle.
Many automotive vehicles have a convertible top or roof that has a pliable fabric covering stretched over an underlying frame. Often these convertible tops include a number one roof bow which, when the convertible top is in the fully closed position, is removably fastened to the front windshield header of the automotive vehicle. The convertible top frames also generally include number two, three and four roof bows, and optionally a number five roof bow. Each of the bows are pivotally affixed to linkages that are pivotally affixed to each other to allow the convertible top to move from the fully opened to the fully closed position. These frames are commonly known as top stack mechanisms.
Some traditional convertible tops are operated by electric motors that drive gears adjacent rear rail portions that are coupled to the vehicle body. One such example is U.S. Pat. No. 5,772,274, entitled xe2x80x9cMotorized Drive System for a Convertible Roof of an Automotive Vehicle,xe2x80x9d which issued to Tokarz on Jun. 30, 1998; this patent is incorporated by reference herein. When various conventional convertible tops are in the fully opened position, a soft or rigid roof cover may be placed over the stowed convertible top.
It is often difficult to package traditional top stack mechanism systems which include a rigid roof cover that will open and allow the convertible top to be stowed below the roof cover. A convertible top with a moveable five bow is particularly difficult to move below the roof cover and out of the way. Also, simultaneously moving the five bow out of the way while moving the roof cover can be difficult. Furthermore, some traditional rigid roof covers are not able to move into a fully flush position with the rest of the vehicle body when the top is retracted and the roof cover is closed. In particular, when the convertible top is in the fully opened position, a closed roof cover usually rests on top of the still upwardly angled (toward the rear of the vehicle) and partially projecting convertible top thereby not allowing a flush or aesthetically pleasing closed roof cover and often requiring a soft rather than rigid roof cover. One such example is U.S. Pat. No. 5,161,853 entitled xe2x80x9cConvertible Top with Improved Geometry,xe2x80x9d which issued to Alexander et al. on Nov. 19, 1992; this patent is incorporated by reference herein.
In accordance with the present invention, the roof cover closes generally flush with the remainder of the adjacent body panels of the vehicle. A convertible roof employs a top stack mechanism and a generally rigid roof cover. Furthermore, the frame may be stowed under a rigid roof cover. In another aspect of the present invention, the top stack mechanism employs a rearmost roof bow which is moved from above a roof cover to allow the roof cover to open, and then the entire top stack mechanism retracts into a storage area. A further aspect of the present invention provides a lost motion coupling of the top stack mechanism to the vehicle body. In yet another aspect of the present invention, a fluid powered actuator controls movement of the rearmost roof bow relative to the remainder of the top stack mechanism.
The top stack mechanism of the present invention is advantageous over conventional systems since the rearmost roof bow of the present invention can be moved independently of the other bows of the convertible top. The fluid powered actuator allows for independent movement of the rearmost roof bow. In addition, the fluid powered actuator provides enough force to hold the rearmost roof bow in position at any point in its movement. Therefore, the fluid powered actuator does not need to be assisted by latches to hold the rear most roof bow in over the roof cover when the top stack mechanism is in the closed position, unlike many electric motor actuators. Also, the fluid powered actuator allows for a smaller mechanism as opposed to other systems. The roof cover is moved out of the way before the convertible top is retracted into the roof storage area. Additionally, the top stack mechanism is stowed past horizontal to allow the rigid roof cover to rest flush with the remainder of the body of the vehicle for a smooth and generally uninterrupted appearance of the exterior of the vehicle. Rather than simply rotating, a portion of the top stack mechanism also slides horizontally and vertically thereby moving the top stack mechanism below a horizontal plane. Therefore, the roof cover may rest evenly with the rearmost section (when stowed) of the body panels without disrupting the exterior lines of the automotive vehicle body. These and other advantages and benefits of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings and claims.